单纯疱疹病毒I型胸苷激酶基因部分缺失重组质粒的构建？…

目的：构建ＨＳＶ－１型胸苷激酶基因部分缺失的重组质粒并进行序列测定。方法：以ｐＵＣ１８／ＴＫ重组质粒ＤＮＡ为模板,用ＰＣＲ方法扩增ＴＫ５＇端５０３ｂｐ基因片段,并将扩增的片段克隆入载体ｐＵＣ１８中（ｐＵＣ１８／ＴＫ１）;用ＰｓｔＩ和ＨｉｎｄⅢ双酶切ｐＵＣ１８／ＴＫ,获得ＴＫ３＇端３８３ｂｐ片段,将此酶切片克隆入ｐＵＣ１８／ＴＫ１中,并进行测序。结果：构建成重组质粒ｐＵＣ１８／ＴＫ＾－。经酶切鉴定获     

单纯疱疹病毒I型胸苷激酶基因在大肠杆菌中的融合表达

用ＥｃｏＲ Ⅰ和Ｈｉｎｄ Ⅲ双酶切已构建的含单纯疱疹病毒Ｉ 型胸苷激酶（ ＨＳＶ１ ＴＫ） 基因的ｐ ＵＣ１８／ＴＫ 质粒，将切出的ＴＫ 基因片段克隆入原核表达载体ｐ ＷＲ４５０１ 中，构建成ＨＳＶ１ ＴＫ 基因重组表达质粒ｐ ＷＲ４５０１／ＴＫ。以ＨＳＶ１ ＴＫ 特异性引物ＴＫ１ Ｆｏｒ 和ＴＫ２ Ｒｅｖ 进行ＰＣＲ 鉴定可扩增出预期的５０３ ｂｐ 的ＴＫ 基因编码区部分序列；ＥｃｏＲ Ⅰ和Ｈｉｎｄ Ⅲ双酶切质粒ｐ ＷＲ４５０１／ ＴＫ， 可切出约１１５０ｂｐ 的ＤＮＡ 片段， 表明重组质粒中已插入ＨＳＶ１ ＴＫ基因片段。用ＩＰＴＧ 诱导ｐ ＷＲ４５０１／ＴＫ／ＪＭ１０９ ，表达出相对分子质量（ Ｍｒ） 约为９７ ０００ 的ＴＫ 和β半乳糖苷酶（ Ｍｒ５５ ０００） 融合蛋白。薄层扫描显示，该融合蛋白含量占菌体蛋白总量的２７ ．４７ ％ 。     

单纯疱疹病毒Ⅰ型SM44株胸苷激酶基因的克隆及序列测定

为了分离、克隆单纯疱疹病毒Ⅰ型（ＨＳＶ－１）ＳＭ４４株胸苷激酶基因（ＴＫ）,采用原代兔婴肾细胞培养ＨＳＶ－Ｉ ＳＭ４４株病毒,提取病毒核酸作为模板,设计了ＨＳＶ－１ ＴＫ基因的上、下游引物,在引物的５‘端分别引入ＢａｍＨ１和ＥｃｏＲ１限制性内切酶位点,通过ＰＣＲ方法扩增出ＴＫ基因,经ＢａｍＨ Ｉ／ＥｃｏＲ １双酶切与ＰＵＣ１９质粒载体相连接,构建重组体转化受体菌ＪＭ１０９,通过筛选和酶切鉴定,获得     

IL—2／HBV PreS融合基因的克隆及序列测定

目的：获得ＩＬ－２／ＨＢＶｐｒｅＳ融合基因克隆，为表达ＩＬ－２／ＨＢＶｐｒｅＳ融合蛋白奠定基础，方法：用ＰＣＲ方法从乙肝全序列中扩增ＨＢＶｐｒｅＳ基因片段，并克隆入带ＩＬ－２基因的ｐｌｙ５质粒中，挑出的阳性克隆再亚克隆到ｐＵＣ１８中进行序列测定。结果：基因全长９３０ｂｐ，编码３１０个氨基酸，序列内有起始码和终止码。结论：所克隆的基因为ＩＬ－２与ＨＢＶｐｒｅＳ的融合基因。     

小鼠BMP—McAb可变区基因的体外扩增,克隆与序列分析

从体外培养的ＢＭＰＭｃＡｂ杂交瘤中提取细胞总ＲＮＡ，反转录成ｃＤＮＡ。以ｃＤＮＡ为模板，利用两对根据免疫球蛋白重链与轻链可变区５′端序列和Ｊ区序列设计合成的引物，通过ＰＣＲ方法，扩增出抗体重链、轻链可变区基因片段（ＶＨ，ＶＬ）。将扩增产物分别克隆入ｐＵＣ１８，ｐＵＣ１９质粒，筛选出阳性克隆，利用双脱氧链终止法进行序列测定，经计算机分析，ＶＨ基因全长为３４５ｂｐ，编码１１５个氨基酸；ＶＬ基因全长为３１５ｂｐ，编码１０５个氨基酸。     

粒细胞—巨噬细胞集落刺激因子与HBsAg融合蛋白基因的 …

目的 研究粒细胞－巨噬细胞集落刺激因子（ＧＭ－ＣＳＦ）的免疫活性。方法 用聚合酶链反应（ＰＣＲ）技术扩增出粒细胞－巨噬细胞集落刺激因子（ＧＭ－ＣＳＦ）３８４ｂｐ的基因片段及ＨＢｓＡｇ８４６ｂｐ基因片段，扩增产物经柱纯化后，由Ｔ４ＤＮＡ酶连结因子１２３０ｂｐ的片段，将此片段命名为ＬＧＨ，克隆到ｐＵＣ１９质粒中，利用菌落ＰＣＲ法快速筛选阳性克隆及限制酶切鉴定片段的大小。结果 该基因全长１２３０ｂｐ，经     

庚型肝炎病毒NS3蛋白在大肠杆菌中的表达

目的　获取具备免疫反应原性的庚型肝炎病毒ＮＳ３ 抗原。方法　从重组质粒Ｉｗｑ２利用ＰＣＲ 反应扩增出ＧＢＶＣ／ＨＧＶ ＮＳ３ 基因片段,克隆至表达载体ｐＰＲＯＥＸ ＨＴａ 后进行核苷酸序列测定,待鉴定正确后经ＩＰＴＧ 诱导重组工程菌,用ＳＤＳＰＡＧＥ 和Ｗｅｓｔｅｒｎ ｂｌｏｔ 对重组蛋白进行鉴定。结果　酶切鉴定和核苷酸序列测定结果表明成功地构建了重组工程菌ｐＨＴＮＳ３／ ＤＨ５α且克隆的基因片段为ＧＢＶＣ／ＨＧＶ ＮＳ３ 基因片段。ＳＤＳＰＡＧＥ 分析诱导表达产物发现在相对分子质量约４３ ８１０处有一条明显的蛋白表达带,占菌体总量的１７ ．７ ％ 。用ＮｉＮＴＡ 亲和层析柱快捷地获得了纯化的重组蛋白。Ｗｅｓｔｅｒｎ ｂｌｏｔ 鉴定发现重组蛋白可与ＧＢＶＣ／ＨＧＶ ＲＮＡ 阳性病人血清发生抗原抗体反应。结论　获得了具备免疫反应原性的ＧＢＶＣ／ＨＧＶ ＮＳ３ 抗原,该重组蛋白可用于ＧＢＶＣ／ＨＧＶ 感染的检测。     

抗HSVgc单克隆抗体V_2基因的扩增、克隆及序列测定

本文从分泌具有高中和活性和高保护作用的抗ＨＳＶ－１／ＨＳＶ－２型共同性糖蛋白Ｃ的鼠源性单克隆抗体（ＭｃＡｂ）的杂交瘤细胞１Ａ１２中提取胞浆总ＲＮＡ，以Ｏｌｉｇｏ（ｄＴ）１５为引物逆转录合成ｃＤＮＡ，用一对鼠抗体Ｋ链通用引物进行ＰＣＲ，扩增出１Ａ１２ＶＬ基因，并克隆入ｐＵＣ１８质粒中。序列分析结果表明，１Ａ１２ＶＬ基因由３３０ｂｐ组成，编码１１０个氨基酸，隶属小鼠轻链ｋ链４组。     

rBPI23基因克隆与鉴定

ｒＢＰＩ２３基因（ＢＰＩ６０ｂｐ）克隆与鉴定。方法：采用ＲＴ－ＰＣＲ技术,从ＨＬ－６０细胞ｍＲＮＡ中扩增编码ＢＰＩＮ端１９９个氨基酸的基因片段,经酶切后通过连接反应构建重组克隆载体,测序鉴定。结果：ＲＴ－ＰＣＲ获得预期的扩增产物－ＢＰＬ６０ｂｐ基因片段。成功构建ＰＵＣ１８－ＢＰＩ１８０、ＰＵＣ１８－＝ＢＰＩ４２０重组克隆载体,酶切、酶谱分析与预期结果相符。ＤＮＡ测序结果与文献报道一致,结论：ＰＵＣ     

致肾盂肾炎大肠杆菌papA基因的克隆及序列分析

目的 对致肾盂肾炎大肠杆菌（ＵＰＥＣ）１３２株的ｐａｐＡ基因进行克隆和序列分析。方法 根据Ｆ１３型ｐａｐＡ基因序列设计引物,并在二引物５′端加上限制性内切酶ＥｃｏＲⅠ和ＢａｎＨⅠ的酶切位点。采用此引物扩增１３２菌株ｐ菌毛粘附基因群的ｐａｐＡ基因,扩增产物克隆人质粒,选取阳性重组质粒进行核苷酸序列分析。结果 ＵＰＥＣ１３２株经ＰＣＲ法扩增获得约７００ｂｐ的ｐａｐＡ片段,经克隆获得阳性重组质粒ｐＣＴ２     

Detection of ultrarare somatic mutation in the human TP53 gene by bidirectional pyrophosphorolysis-activated polymerization allele-specific amplification

The detection of ultra-rare mutation in the presence of excess amounts of normal genomic DNA is highly advantageous in a number of circumstances, including: 1) identification of minimal residual disease for improved cancer chemotherapy; 2) measurement of mutation load to assess environmental mutagen exposure or endogenous DNA repair; and 3) prenatal diagnosis of paternally-derived mutations within fetal cells in the maternal circulation. Bidirectional pyrophosphorolysis activated polymerization allele-specific amplification (Bi-PAP-A) utilizes two opposing 3'-terminal blocked oligonucleotides (P(*)s) with 1 nucleotide overlap at their 3' termini. The selectivity of Bi-PAP-A derives from the serial coupling of pyrophosphorolysis and DNA polymerization. A total of 13 Bi-PAP-A assays were developed and validated for the human p53 gene (TP53). The sensitivity and specificity of each assay were determined with mutated and wild-type DNA templates, respectively. Bi-PAP-A has a sensitivity of one molecule for most assays and a selectivity (sensitivity:specificity) greater than 1:10(7)-1:10(9) for four of all six mutation types. Four assays with high selectivity were used to detect rare somatic mutations in blood white cells. The silent g.13147C>G (p.R156) mutation was present at an estimated frequency of 1.1 x 10(-7). The g.14523A>T (p.E285V), g.14487G>C (p.R273P), and g.14060G>C (p.G245R) mutations were undetectable with frequencies less than 2.0 x 10(-8). We conclude that Bi-PAP-A is a general and rapid method for detecting ultra-rare mutations.     

Identification of WASP mutations in 14 Spanish families with Wiskott‐Aldrich syndrome

The Wiskott‐Aldrich syndrome (WAS) is an X‐linked immunodeficiency caused by mutations in the WASP gene. The disease is known to be associated with extensive clinical variability, and mutation studies indicate that genotypes are also highly variant among WAS patients. In this study, we performed mutation analysis of the WASP gene in 14 unrelated Spanish families by single strand conformation analysis (SSCA) and sequencing, resulting in the identification of a novel mutation and nine known mutations. No mutation was identified in one family. The ten different mutations include point mutations resulting in amino acid substitutions, stop codons, and small deletions and insertions causing frameshifts. Missense mutations were preferentially located in the amino‐terminal part of the protein, exons 2 and 4, whereas stop and frameshift mutations were located in the carboxyl‐terminal region, exons 10 and 11. However, in two families, two missense mutations in exon 11 were identified. Our study demonstrates that WASP genotypes have some concordance with the patients' phenotypes, although mutation 1019delC, identified in a family with several affected members, resulted in high intrafamilial clinical variability. © 2001 Wiley‐Liss, Inc.     

Hansa: an automated method for discriminating disease and neutral human nsSNPs

Variations are mostly due to nonsynonymous single nucleotide polymorphisms (nsSNPs), some of which are associated with certain diseases. Phenotypic effects of a large number of nsSNPs have not been characterized. Although several methods have been developed to predict the effects of nsSNPs as "disease" or "neutral," there is still a need for development of methods with improved prediction accuracies. We, therefore, developed a support vector machine (SVM) based method named Hansa which uses a novel set of discriminatory features to classify nsSNPs into disease (pathogenic) and benign (neutral) types. Validation studies on a benchmark dataset and further on an independent dataset of well-characterized known disease and neutral mutations show that Hansa outperforms the other known methods. For example, fivefold cross-validation studies using the benchmark HumVar dataset reveal that at the false positive rate (FPR) of 20% Hansa yields a true positive rate (TPR) of 82% that is about 10% higher than the best-known method. Hansa is available in the form of a web server at http://hansa.cdfd.org.in:8080.     

Distribution of KRAS and BRAF mutations in Moroccan patients with advanced colorectal cancer

Targeted therapies have an increasing importance in digestive oncology. To our knowledge, we are the first to report the distribution of KRAS and BRAF mutations in Moroccan patients with advanced colorectal cancer (CRC) in order to introduce targeted therapy in the arsenal of therapeutic modalities for management of this cancer in Morocco. In this study, 92 samples obtained from patients with CRC were tested for the presence of the nine most common mutations in the KRAS gene and BRAF gene. Among the tested patients, 76.09% of patients had wt-KRAS genotype and 23.91% were KRAS mutants and the majority of mutations would result in an amino acid substitution of glycine by aspartic acid (68.2%) The predominant mutations are G>A transitions and G>T transversions. Around 5% (5.43%) of the tested patients bore the V600E mutation in BRAF gene. Only one patient showing to have the V600E mutation in BRAF was also mutated-KRAS. Summing up the results about the KRAS and the BRAF mutation carriers from our study, the portion of potentially non responsive patients for the anti-EGFR treatment is 28.26%.     

PAP: detection of ultra rare mutations depends on P* oligonucleotides: "sleeping beauties" awakened by the kiss of pyrophosphorolysis

Pyrophosphorolysis-activated polymerization (PAP) was initially developed to enhance the specificity of allele-specific PCR for detection of known mutations in the presence of a great excess of wild-type allele. The high specificity of PAP derives from the serial coupling of activation of a 3' blocked pyrophosphorolysis-activable oligonucleotide (P(*)) with extension of the unblocked, activated P(*). In theory, PAP can detect a copy of a single base mutation present in 3x10(11) copies of the wild-type allele. In practice, the selectivity of detection is limited by polymerase extension errors, a bypass reaction, from the unblocked oligonucleotide annealed to the opposing strand. Bi-directional PAP allele-specific amplification (Bi-PAP-A) is a derivative of PAP that uses two opposing pyrophosphorolysis activable oligonucleotides (P(*)) with one nucleotide overlap at their 3' termini. This eliminates the problematic bypass reaction. The selectivity of Bi-PAP-A was examined using lambda phage DNA as a model system. Bi-PAP-A selectively detected two copies of a rare mutated allele in the presence of at least 2x10(9) copies of the wild-type lambda phage DNA. We then applied Bi-PAP-A to direct detection of spontaneous somatic mutations in the lacI transgene in BigBlue transgenic mice at a frequency as low as 3x10(-9). A 370-fold variation in the frequency of a specific somatic mutation among different mouse samples was found, implying hyper-Poisson variance and clonal expansion of mutation occurring during early development. Bi-PAP-A is a simple, rapid, and general method capable of automation and particularly suited to detection of ultra rare mutations. We also show that P(*) oligonucleotides have the novel and unexpected property of high specificity to mismatches with the template throughout lengths of the P(*). Thus, PAP also can form the basis of microarray-based scanning or resequencing methods to detect virtually all mutations.     

The challenge of documenting mutation across the genome: the human genome variation society approach

New methods for the detection of mutations and the completion of the human genome sequencing project have contributed to an exponential rise in variation information that must be collected, quality controlled, documented, and stored safely to ensure future availability to health care professionals, researchers, and others. There may be anywhere from one to more than 1,000 mutations in any given gene. To date, this information has been collected by general databases such as Online Mendelian Inheritance in Man (OMIM) or the Human Gene Mutation Database (HGMD), which collect only published mutations and, in the case of OMIM, selected published mutations. Unpublished mutations have made their way into Locus Specific Databases (LSDBs), and these can often contain as many unpublished mutations as published ones, in addition to other more detailed gene-specific information. LSDBs, however, do not exist for all genes at this time. Through their interactions, a number of members of the Human Genome Variation Society (HGVS) have developed nomenclature, standard software to curate mutations in gene specific databases, a WayStation to collect and review new mutations from research and diagnostic laboratories, and central databases to store and display these mutations and their associated phenotypes. Nomenclature is now well defined for the commonest types of mutation, with work continuing on systematically naming the more complex types. Other projects, such as dedicated specialized software for LSDBs, are in the early stages of development.     

Mutation rate: A simple concept has become complex

The factors that cause new mutations or affect the rate at which they occur have important implications for many areas of genetics. But recent work on phenomena such as premeiotic mutations, which yield a cluster of identical new mutants at the same time, led us to realize that researchers are using the term “mutation rate” in different, and sometimes contradictory, ways. One premeiotic genetic change may ultimately yield several new mutant offspring, but should this be considered one new mutation or many? The way the data are handled in analyses can have a significant effect on the results. How, then, does one handle clusters in the estimation of mutation rates? We explore this question and propose that geneticists begin to distinguish clearly between three different phenomena that to this point have been given the same name: the initial prerepair “genetic damage rate,” the postrepair “mutational event rate,” and the observed “mutation rate” as it is expressed in the proportion of new mutant offspring. We believe that all new mutant offspring should be counted when estimating mutation rate, irrespective of when in the developmental cycle it is believed that the initial mutational event occurred. Environ. Mol. Mutagen. 32: 292–300, 1998 © 1998 Wiley-Liss, Inc.     

Mutations in the factor IX gene (F9) during the past 150 years have relative rates similar to ancient mutations

Pollutants and dietary mutagens have been associated with somatic mutation and cancer, but the extent of their influence on germline mutation is not clear. Since deleterious germline mutations can be transmitted for thousands of years, any influence on germline mutation from the vast increase in man‐made chemicals of the past 150 years would be an important public health issue. Observed disease causing mutations in the X‐linked factor IX gene (F9) of hemophilia B patients originated predominantly in the past 150 years, since the half‐life of these mutations in human populations had been about two generations before effective treatment became available about a generation ago. Recent changes in germline mutational processes may be detected by comparison of the observed hemophilia B causing mutation pattern in F9 with the pattern of neutral polymorphisms which occurred over a much longer period of time. By scanning a total of 1.5 megabases of deep intronic regions of F9 in the genomic DNA from 84 individuals, 42 neutral polymorphisms were found in 23 haplotypes that differed by at least 11 mutations from the ancestral primate haplotype. By sequencing F9 in seven non‐human primates, 39 of these polymorphisms were characterized as ancient mutations relative to a unanimous ancestral primate allele. This ancient mutation pattern was compared to the recent pattern of hemophilia B causing mutations. Remarkably, no significant difference was found (P=0.5), suggesting that the vast increase in man‐made chemicals during the past 150 years has not had a major impact on the pattern of human germline mutation. This result is consistent with the hypothesis that endogenous processes dominate germline mutation. Hum Mutat 19:49–57, 2002. © 2001 Wiley‐Liss, Inc.     

Mutation analysis of 11 Chinese patients with attenuated mucopolysaccharidosis type Ⅰ

Objective Mucopolysaccharidosis type Ⅰ (MPS Ⅰ ) is an autosomal recessive diseaseresulting from the deficiency in the lysosomal enzyme α-L-iduronidase (IDUA). The present study was conducted to identify IDUA gene mutations in attenuated (MPS Ⅰ H/S and MPS Ⅰ S) patients with MPS Ⅰin northern China. Methods Fourteen exons with adjacent intronic sequences of the IDUA gene in 11 MPS Ⅰ patients were amplified by polymerase chain reaction (PCR), and the PCR products were sequenced directly and origin analysis was conducted. Results Seven mutations were detected in the 11 MPS Ⅰ patients, i.e., c. 236 C＞T(p. A79V), c. 266 G＞A(p. R89Q), c. 265 C＞T(p. R89W), c. 532G＞A(p.E178K), c. 589G＞A(p. G197S), c. 1037T＞G(p. L346R), and c. 1877 G＞A(p. W626X). All of them were known mutations. Six patients were homozygotes and 1 was heterozygote with nonsense mutation. In addition, 9 reported single nucleotide polymorphism (SNP) were detected, i. e., p. A8, p. A20, p. H33Q,p. R105Q, p. A314, p. A361T, p. T388, p. T410 and p. V454I. Conclusion The mutation spectrum of the IDUA gene in attenuated MPS Ⅰ Chinese patients may be different from that in patients from other countries.     

Mutation analysis of 11 Chinese patients with attenuated mucopolysaccharidosis type Ⅰ

Objective Mucopolysaccharidosis type Ⅰ (MPS Ⅰ ) is an autosomal recessive diseaseresulting from the deficiency in the lysosomal enzyme α-L-iduronidase (IDUA). The present study was conducted to identify IDUA gene mutations in attenuated (MPS Ⅰ H/S and MPS Ⅰ S) patients with MPS Ⅰin northern China. Methods Fourteen exons with adjacent intronic sequences of the IDUA gene in 11 MPS Ⅰ patients were amplified by polymerase chain reaction (PCR), and the PCR products were sequenced directly and origin analysis was conducted. Results Seven mutations were detected in the 11 MPS Ⅰ patients, i.e., c. 236 C＞T(p. A79V), c. 266 G＞A(p. R89Q), c. 265 C＞T(p. R89W), c. 532G＞A(p.E178K), c. 589G＞A(p. G197S), c. 1037T＞G(p. L346R), and c. 1877 G＞A(p. W626X). All of them were known mutations. Six patients were homozygotes and 1 was heterozygote with nonsense mutation. In addition, 9 reported single nucleotide polymorphism (SNP) were detected, i. e., p. A8, p. A20, p. H33Q,p. R105Q, p. A314, p. A361T, p. T388, p. T410 and p. V454I. Conclusion The mutation spectrum of the IDUA gene in attenuated MPS Ⅰ Chinese patients may be different from that in patients from other countries.